johnlocke wrote:Using the latest battery chemistry (NMC 811) you can get 1250 charge/discharge cycles (2.8 vdc to 4.2 vdc I.E. 100% discharge) at 45 degrees C. before you lose 20% capacity. And that's at 1C charge and discharge rates. Goes up to 1500 cycles for 20 degrees C. For a 60 KWH battery, that works out to 250K miles. What's not mentioned is long term deterioration as these kind of tests are run end to end over a period of months. If long term storage is not a problem this could be a "lifetime" battery. With 200 amp charging available, TMS will still be necessary while charging to prevent overheating the battery during DC Fast Charging during road trips. You might get away without a TMS while home charging overnight or even during normal driving but DCFC is going to require it anyway so you might as well make use of it.
If you expect to get the DCFC time down to 15 to 30 minutes, you have to use a 2-4 C charge rate which is not a problem for the battery to accept but will definitely heat up the battery. That's why you need the TMS.
This is the same mistake Nissan made when testing the original pack. Pack cycles fine in a bonfire but when faced with the realities of life, it flopped. Why? because we don't charge and then drive. We charge.............................. and then drive a teeny bit. park, sit sit sit, then drive a teeny bit more.
I know a Bolter who plans to charge one day a week because of how much range he has. I told him, he would be better off to charge a few hours a day or every other day. Why charge to full if you don't have to? but he doesn't care. He has 150 more miles of range than he needs.
But then again, you look at random Teslas at 300,000 miles and everyone is shocked but why is it a surprise? Unlike us, their driving habits DO resemble a cycle test!
I know a Uberite who did 100,000 miles on his LEAF with 12 bars... again cause his driving patterns resemble a cycle test; fast charge, drive, fast charge, drive... sleep every other day.